Geneticist Perry Cregan and other ARS scientists
are part of a team that has sequenced the majority of the soybean genome,
providing an unprecedented look into how this important legume crop converts
sunlight, water, carbon dioxide and nitrogen into protein and oil. Click the
image for more information about it.

USDA Scientists, Cooperators Sequence Soy Genome

WASHINGTON, January 13, 2010U.S.
Department of Agriculture (USDA) scientists are part of a team that has
sequenced the majority of the soybean genome, providing an unprecedented look
into how this important legume crop converts four critical
ingredientssunlight, water, carbon dioxide and nitrogeninto protein
and oil, the basic building blocks for many consumer products. The research
team from 18 federal, state, public and private organizations published their
research today in the journal Nature.

"Soybean and other legumes play a critical role in global food security
and human health and are used in a wide range of products, from tofu, soy
flour, meat substitutes and soy milk to soy oil-based printing ink and
biodiesel," said Molly Jahn, USDA Deputy Under Secretary for
Research, Education and Economics.
"This new information about soybean's genetic makeup could lead to plants
that produce more beans that contain more protein and oil, better adapt to
adverse environmental conditions, or are more resistant to diseases."

This sequencing of the soy genome is the culmination of more than 15 years
of collaborative research. The team used a so-called "whole-genome
shotgun" (WGS) approach to sequence 85 percent of the 1.1 billion
nucleotide base pairs that spell out soy's entire DNA code. The sequence also
provides researchers with a critical reference to use in deciphering the
genetics of some 20,000 other legume species.

According to USDA's Shoemaker, who is with the ARS
Corn
Insects and Crop Genetics Research Unit in Ames, Iowa, integrating the new
sequence with existing physical and genetic maps of soy will move researchers
closer to linking observable physical traits of soy to their associated genes
and allelesalternate versions of genes. Ultimately, this will speed the
development of new soybean cultivars offering higher seed yields, increased
protein and oil contents, better adaptability and improved disease resistance,
particularly to Asian soybean rust (ASR), which threatens America's $27 billion
soy crop.

"Overlaying the sequence onto available maps will expedite
identification and orientation of genetic markers such as single nucleotide
polymorphisms, which are often located near genes that control agronomically
important traits," Shoemaker said.

Using such markers, soy breeders can rapidly determine which offspring
plants have inherited these traits without growing them to maturity, saving
time, money and resources.

"We've mapped the locales for about 90 important traits affecting
soybean growth and development, seed yield, seed protein and oil, and disease
resistance, to name but a few," Shoemaker added. "With this
high-quality sequence, we now have access to candidate genes that we've never
had before, which will enable us to look at their patterns of expression,
develop molecular markers to track them in breeding programs, and work with
them to determine their function or modify them to improve their
function."

Some key discoveries already gleaned from the whole-genome sequence include
the first soybean gene conferring resistance to ASR, which can cause soy losses
of 10 to 80 percent; a mutation that could make soybeans easier to digest by
producing lower levels of a carbohydrate called stachyose; a mutation for
higher levels of production of the enzyme phytase that could enable livestock
to absorb more phosphorus from soybean feed so less gets excreted as a
potential water contaminant; and 52 genes that orchestrate development of soy
plant root nodules, where symbiotic bacteria transform atmospheric nitrogen
into a form soy and other crops can use for their growth and development.